<?php
class Ascii
{

	public static function decode($str)
	{
		preg_match_all( "/(d{2,5})/", $str,$a);
		$a = $a[0];
		foreach ($a as $dec)
		{
			if ($dec < 128)
			{
				$utf .= chr($dec);
			}
			else if ($dec < 2048)
			{
				$utf .= chr(192 + (($dec - ($dec % 64)) / 64));
				$utf .= chr(128 + ($dec % 64));
			}
			else
			{
				$utf .= chr(224 + (($dec - ($dec % 4096)) / 4096));
				$utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64));
				$utf .= chr(128 + ($dec % 64));
			}
		}
		return $utf;
	}

	public static function encode($c)
	{
		$len = strlen($c);
		$a = 0;
		while ($a < $len)
		{
			$ud = 0;
			if (ord($c{$a}) >=0 && ord($c{$a})<=127)
			{
				$ud = ord($c{$a});
				$a += 1;
			}
			else if (ord($c{$a}) >=192 && ord($c{$a})<=223)
			{
				$ud = (ord($c{$a})-192)*64 + (ord($c{$a+1})-128);
				$a += 2;
			}
			else if (ord($c{$a}) >=224 && ord($c{$a})<=239)
			{
				$ud = (ord($c{$a})-224)*4096 + (ord($c{$a+1})-128)*64 + (ord($c{$a+2})-128);
				$a += 3;
			}
			else if (ord($c{$a}) >=240 && ord($c{$a})<=247)
			{
				$ud = (ord($c{$a})-240)*262144 + (ord($c{$a+1})-128)*4096 + (ord($c{$a+2})-128)*64 + (ord($c{$a+3})-128);
				$a += 4;
			}
			else if (ord($c{$a}) >=248 && ord($c{$a})<=251)
			{
				$ud = (ord($c{$a})-248)*16777216 + (ord($c{$a+1})-128)*262144 + (ord($c{$a+2})-128)*4096 + (ord($c{$a+3})-128)*64 + (ord($c{$a+4})-128);
				$a += 5;
			}
			else if (ord($c{$a}) >=252 && ord($c{$a})<=253)
			{
				$ud = (ord($c{$a})-252)*1073741824 + (ord($c{$a+1})-128)*16777216 + (ord($c{$a+2})-128)*262144 + (ord($c{$a+3})-128)*4096 + (ord($c{$a+4})-128)*64 + (ord($c{$a+5})-128);
				$a += 6;
			}
			else if (ord($c{$a}) >=254 && ord($c{$a})<=255)
			{ //error
				$ud = false;
			}
			$scill .= "&#$ud;";
		}
		return $scill;
	}

}